JPH1089461A - Automatic transmission control unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reset a line pressure solenoid SL turned to an unintended off-state at the time of driving a self-starting motor, to a normal regular on-state without resting on a detection circuit of battery voltage. SOLUTION: When a key switch is turned on, an automatic transmission control unit 10 feeds a line pressure solenoid SL with high voltage as line as three seconds and, after having it made into overexcitation, a state of holding excitation is maintained with low voltage, but if such a fact that a self-starting is in driving is judged from the engine speed, it is set to such normal control as repeating those of overexcitation, holding excitation and switch-off at 50Hz. In time of driving the self-starting motor, even if the battery voltage goes down and the line pressure solenoid SL of the holding excitation comes to a state of being turned off, it is quickly reset to a normal regular on-state by the intermittent overexcitation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to an automatic transmission control device that constantly keeps a line pressure solenoid of an automatic transmission in an ON state when the engine is stopped.

[0002]

2. Description of the Related Art The line pressure of an automatic transmission during traveling is adjusted by an automatic transmission control device in accordance with a vehicle speed and a throttle opening. The line pressure is increased as the throttle opening increases. The automatic transmission control device adjusts the line pressure by increasing or decreasing the ON / OFF duty ratio of the line pressure solenoid. Specifically, the cycle of overexcitation, holding excitation, and OFF of the line pressure solenoid is repeated at a constant cycle, and the ON / OFF time ratio is set to a predetermined control amount, and the line pressure is set to the target value. Induce.

The automatic transmission control device does not require the line pressure when the vehicle is stopped and the engine is stopped.
Keep the line pressure solenoid in the holding excitation state and turn ON /
The OFF operation is stopped so that noise is not emitted from the line pressure solenoid. At this time, the line pressure solenoid is released from the running control (normal control, duty ratio control) and is always in the ON state, and the line pressure drops to the minimum level.

Japanese Patent Laid-Open Publication No. Hei 3-9169 discloses a control for stopping the driving of the line pressure solenoid under the condition that the line pressure becomes unnecessary in the automatic transmission, thereby suppressing the consumption and noise of the line pressure solenoid. . Here, the line pressure solenoid is always turned off.

[0005]

In a line pressure solenoid whose duty ratio is controlled, a large current flows when overexcitation is continued, and the coil life is shortened. Therefore, when the line pressure solenoid is always turned on, for example, After the key switch is turned on, a high overexcitation voltage is applied for a very short time to turn on the line pressure solenoid, and thereafter, the ON state is maintained at a low hold excitation voltage. However, when the engine is started in such an always-on state, the battery voltage temporarily drops due to the large current taken out by the starter motor, the driving voltage of the line pressure solenoid also drops, and the line pressure solenoid turns off. It is possible that

Here, the low voltage of the holding excitation is sufficient to maintain the ON state against the reaction force of the return spring of the line pressure solenoid, but the compression of the return spring causes the line pressure solenoid in the OFF state to contract. Is not enough to turn ON. Therefore, even if the driving of the starter motor is stopped and the driving voltage of the line pressure solenoid is restored to the normal holding excitation level together with the battery voltage, the line pressure solenoid does not return to the normal ON state but remains in the OFF state.

In view of the above, there has been proposed a control for detecting a battery voltage and performing an intermittent overexcitation during a period in which the battery voltage is below a predetermined value, thereby returning the line pressure solenoid, which has been in the OFF state, to the ON state. But,
In this case, it is necessary to provide a battery voltage detection circuit in the automatic transmission control device.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an automatic transmission control device capable of returning to an ON state when a line pressure solenoid that is always ON is turned OFF due to a voltage drop without detecting a battery voltage. I have.

[0009]

According to a first aspect of the present invention, there is provided an automatic transmission control device for keeping a line pressure solenoid of an automatic transmission in an on state at all times when the engine is stopped. The line pressure solenoid continues to be held and excited after the
N control means, an engine speed detecting means for detecting that the engine speed is in a range corresponding to the driving of the starter motor, and an over-excitation of the line pressure solenoid once after the start of the starter motor is detected. And recovery means for performing the above.

According to a second aspect of the present invention, there is provided an automatic transmission control device for continuously holding a line pressure solenoid of an automatic transmission in an ON state when an engine is stopped. A continuous ON control means for continuing the holding excitation state of the pressure solenoid, a cell motor ON detection means for detecting that the key switch is at the cell motor driving position, and an overexcitation of the line pressure solenoid after the driving of the cell motor is detected. Is performed once or more.

According to a third aspect of the present invention, in the configuration of the first or second aspect, the recovery means continues intermittent overexcitation until a predetermined time elapses even if the driving of the starter motor is not detected. .

According to a fourth aspect of the present invention, there is provided an automatic transmission control device for continuously holding a line pressure solenoid of an automatic transmission in an ON state when the engine is stopped, and when the engine stopped state is detected, the vehicle is overrun until the vehicle starts. The excitation of the line pressure solenoid is continuously maintained by intermittent excitation.

[0013]

According to the first aspect of the present invention, when the key switch is turned on, the line pressure solenoid is always turned on. Here, when the starter is driven to start the engine, the engine speed rises from 0,
Until the engine is completely started, the engine speed is in a range lower than the idle speed. Accordingly, the line pressure solenoid is overexcited by detecting that the engine speed is within a specific range during the driving of the cell motor. The line pressure solenoid which has been unintentionally turned off due to a decrease in the battery voltage returns to the on state due to overexcitation.

In the automatic transmission control device according to the second aspect, when the key switch is turned on, the line pressure solenoid is always on.
State. Here, when the key switch is operated to the cell motor driving position, the cell motor is driven and the engine is started. Therefore, it is detected that the key switch is at the start position of the starter motor, and the line pressure solenoid is overexcited. Unintended O due to low battery voltage
The line pressure solenoid in the FF state returns to the ON state due to overexcitation.

In the automatic transmission control device according to the third aspect, the battery voltage does not always return to the normal value immediately after the drive of the starter motor is no longer detected. The intermittent over-excitation is continued until a predetermined time elapses in anticipation of a margin.

In the automatic transmission control device according to the fourth aspect, the short overexcitation is intermittently executed while the line pressure solenoid is maintained in the holding excitation state. Since the line pressure solenoid is not turned off, the line pressure solenoid keeps on as long as the battery voltage does not drop. Even if the battery voltage drops and the line pressure solenoid is turned off, the line pressure solenoid is returned to the on state by overexcitation.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment will be described with reference to FIGS. As shown in FIG. 1, the automatic transmission 12 changes the output of the engine 11 and outputs it to the output shaft 13. The automatic transmission control unit 10 includes a battery 21
The automatic transmission 12 is controlled by receiving power supply from the key switch 22 through the key switch 22. The key switch 22 is provided with a start switch circuit (not shown) for the cell motor of the engine 11, and the start switch circuit is turned on by operating the key to the cell motor drive position. The automatic transmission control unit 10 includes a CPU (arithmetic element) 16
, An input circuit 15, an output circuit 17, and a memory element 18 are arranged. The input circuit 15 converts a signal input from an external sensor, switch, or peripheral device into a digital signal suitable for input conditions of the CPU 16. An analog voltage signal from the throttle sensor of the engine 11 and a frequency signal corresponding to the angular velocity of the engine 11 and the output shaft 13 are input to the input circuit 15.

The output circuit 17 forms an output signal corresponding to each load from various digital signals output from the CPU 16. The memory 18 is controlled by the CPU 16 and holds programs and data processed by the CPU 16. The power supply circuit 19 forms a constant voltage for an electronic circuit from the output voltage of the battery 21. The output circuit 17 operates the line pressure solenoid SL of the automatic transmission 12 using the battery voltage VB, as shown in FIG.

As shown in FIG. 2, the CPU 16 repeats ON / OFF of the transistors Q1 and Q2 of the output circuit 17 at a constant cycle, and controls the duty ratio of the line pressure solenoid SL as shown in FIG. In FIG.
The signal with Q4 indicates the collector voltage of the transistors Q3 and Q4, and VS and IS are the line pressure solenoid SL
And the current flowing through the line pressure solenoid SL.

When the transistor Q2 is turned on, the transistor Q4 is also turned on, and the battery voltage VB is applied to the line pressure solenoid SL, so that a large current flows and the line pressure solenoid SL is overexcited. Subsequently, the transistor Q1
Turns ON, the transistor Q3 also turns ON. At this time, the voltage applied to the line pressure solenoid SL due to the voltage drop of the drop resistor R1 becomes one of the battery voltage VB.
/ 3 or less, and the line pressure solenoid SL is held and excited. The magnetic force of the overexcited coil pushes and retracts the return spring of the line pressure solenoid SL to attract the plunger. The holding excitation holds the attracted plunger against the reaction force of the return spring. If the line pressure solenoid SL is continuously overexcited, a large current flows and the coil is overheated. The holding excitation is insufficient for compressing the return spring to attract the plunger.

In the line pressure control during traveling, the ON / OFF duty ratio of the line pressure solenoid SL is controlled. The CPU 16 calculates the throttle opening from the output of the throttle sensor of the engine 11 and the vehicle speed from the angular velocity signal of the output shaft 13, and adjusts the duty ratio according to the throttle opening and the vehicle speed. As shown in FIG. 3, the cycle of overexcitation, holding excitation, and OFF is repeated at 20 ms (50 Hz). Assuming that the overexcitation is 3 ms, the ratio of the holding excitation and OFF which occupy the remaining 17 ms is changed. At a duty ratio of 100%, the line pressure becomes 0, and at a duty ratio of 15%, the line pressure remains at the original pressure of the oil pump. The line pressure determines a fastening force of a fastening element incorporated in the automatic transmission 12. When the output of the engine 11 rises (the throttle opening increases), the CPU 16 increases the line pressure to secure the necessary fastening force.

FIG. 4 shows the line pressure control during stopping. In the figure, the signal denoted by reference numeral 22 indicates that the key switch 22 is ON.
/ OFF, and a signal with the symbol SM is a signal
1 shows ON / OFF of the cell motor (operation / non-operation of a key to a cell motor driving position). The CPU 16 keeps the line pressure solenoid SL in the ON state while the engine is stopped and the engine is idling. The situation in which the line pressure solenoid SL becomes a noise source in the silence of the engine stop or idle rotation is avoided. That is, immediately after the key switch 22 is turned on at time A, the CPU 16
Is turned on, and the line pressure solenoid SL is over-excited for 3 ms, and thereafter, only the transistor Q1 is kept on to keep the line pressure solenoid SL held and excited. As a result, the line pressure solenoid SL is turned on and released, and the line pressure becomes zero.
Is held.

However, when the cell motor SM is turned on at time B and the battery voltage VB temporarily drops, the magnetic force of the holding excitation decreases, and the reaction force of the return spring of the line pressure solenoid SL can push the plunger back to the OFF state. There is. Therefore, the CPU 16 detects the engine speed NE and, when judging that the engine speed is unique to the driving of the starter motor SM, always stops the ON control and applies the control during traveling. Among the operation sounds of the starter motor, the line pressure solenoid SL cannot be a noticeable noise source. That is, the line pressure solenoid SL repeats the cycle of overexcitation, holding excitation, and OFF at 50 Hz, and the ON / OFF duty ratio is set to a value corresponding to the throttle opening TVO.

On the other hand, when the starter SM is driving the engine 11, the engine speed NE is 300 rpm.
Before and after, when the engine 11 is started, the engine speed NE rapidly rises, and after the engine speed NE exceeds 500 rpm at time C, the engine speed NE shifts to an idle speed of 600 to 1500 rpm. Therefore, when the engine 16 detects the engine speed NE and shifts to the idle rotation state, the CPU 16 always restarts the ON control to suppress the noise of the line pressure solenoid SL again. Thereafter, if the always-on control is stopped at the time E due to the start of the car, the running control is performed.

By the way, even if the engine speed NE rises rapidly, the output of the battery 21 does not always recover to the normal 12 V at the time C exceeding 500 rpm. Therefore, the CPU 16 determines that the engine speed NE is 50
Even if the rotation speed exceeds 0 rpm, the control during traveling is continued and the time TD
(One second), the ON control is restarted at time D at all times.

The control of the first embodiment will be described with reference to FIGS. As shown in FIG. 5, in step 101, it is determined whether or not a shift is being performed. If the shift is in progress, step 108
Then, the specific line pressure control is applied during the shift.
The line pressure at each stage from the start of the shift to the end of the shift is finely set. In the following step 109, the set line pressure pattern is realized by controlling the duty ratio of the line pressure solenoid SL. Thereby, the shift shock accompanying the switching of the fastening element of the automatic transmission 12 is effectively suppressed. If the shift is not being performed, the flow after step 102 is selected, and the above-described control during traveling (normal control) or the always-on control is applied.

In step 102, the throttle opening TVO is calculated from the output of the throttle sensor of the engine 11. In step 103, a comparison table between the throttle opening and the line pressure shown in FIG. 7 is called from the memory 18, and the line pressure P1 corresponding to the throttle opening A1 at that time is obtained. In step 104, a comparison table of the line pressure and the duty ratio shown in FIG. 8 is called from the memory 18, and the duty ratio D1 corresponding to the line pressure P1 obtained in step 103 is obtained.

In step 105, it is determined according to the flowchart shown in FIG. 6 whether to apply the always-on control or the normal control. The flag F is set to 1 when the control is always on, and 0 is set for the normal control. In step 106, whether the flag F is 1 or 0 is identified. If the flag F is 1, the routine proceeds to step 107, and the constant ON control shown in FIG. 4 is performed. If the flag F is 0, the routine proceeds to step 109, and the running control (normal control) shown in FIG. . In step 110, controls other than the line pressure control (shift determination, rearrangement of the fastening element associated with the shift, lockup determination, lockup control, etc.) are executed.

As shown in FIG. 6, in step 121,
It is determined whether or not the throttle opening TVO exceeds 1/8. If it exceeds 1/8, the process proceeds to step 126, but 1 /
If it is less than 8, the routine proceeds to step 122, where it is determined whether or not the engine speed NE is 0. If the engine speed NE is not 0, the routine proceeds to step 123, where it is determined whether or not the engine speed NE is in the range of 600 to 1500 rpm. If the engine speed NE is out of the range of 600 to 1500 rpm, the routine proceeds to step 127. Engine stopped state (NE = 0) or idle rotation state (NE 600-
If it is 1500 rpm), the routine proceeds to step 124, where it is determined whether the vehicle speed VSP exceeds 5 km / h. If the vehicle is substantially stopped (VSP is 5 km / h or less), the routine proceeds to step 125, where the flag F is set to 1. Vehicle speed VSP
If it exceeds 5 km / h, the routine proceeds to step 129.

In step 126, the throttle opening TVO
Is greater than 1.5 / 8. 1.5 / 8
If not, the process proceeds to step 127, where it is determined whether or not the engine speed NE exceeds 1700 rpm. If the engine speed NE is 1700 rpm or less, the routine proceeds to step 128, where the engine speed NE is 200 to 50.
Identify whether it is in the range of 0 rpm. Engine speed NE
Is out of the range of 200 to 500 rpm, step 12
Proceeding to 9, it is determined whether the vehicle speed VSP is less than 7 km / h. Step 1 if the vehicle speed VSP is less than 7 km / h
Proceed to 30. On the other hand, the accelerator pedal depressed state (T
VO is 1.5 / 8 or more), the starting state from the idle rotation state (NE is 1700 rpm or more), the idle rotation (NE is in the range of 200 to 500 rpm), the substantial running state (vehicle speed VSP is 7 km / h or more) ), The routine proceeds to step 134, where the flag F is set to 0.

In step 130, a rise of the engine speed NE accompanying the start of the engine 11 is detected. The engine speed NE is compared with the previous engine speed NE, and the process proceeds to step 132 at a timing exceeding 500 rpm to reset the timer and start time counting. After the engine speed reaches 500 rpm or more, the process proceeds to step 131. When the timer reaches 1 second, the time count is stopped in step 133, the flag F is maintained as it is, and the process of FIG. 6 ends. On the other hand, the process proceeds to step 134 until the timer reaches one second, and the flag F is set to 0. Steps 121 and 12 in the flowcharts of FIGS.
2, 124, 125, 106 and 107 are always O in the present invention.
N control means. Steps 123, 127, 12
8 is the engine speed detecting means of the present invention, step 13
4, 106 and 109 correspond to the recovery means of the present invention.

According to the automatic transmission control unit 10 of the first embodiment, since the line pressure solenoid SL is always turned on when the engine is stopped and the engine is idling, the plunger of the line pressure solenoid SL is controlled as in the normal control. There is no need to worry about generating noise by vibrating at 50 Hz.
Then, as the cell motor is driven, the battery voltage VB
Is reduced and the return spring of the line pressure solenoid SL pushes back the plunger to temporarily turn off, so that normal control is applied, so the ON state is immediately restored by overexcitation and the line pressure rises. Is avoided. Therefore, there is no fear that the driver will take a start under an abnormally high line pressure and feel uncomfortable.

Further, since the engine speed NE used for the control of the automatic transmission 12 is identified to determine the start and end timings of the continuous ON control of the line pressure solenoid SL, a circuit for detecting the battery voltage VB is provided. Is unnecessary,
There is no need to add new wiring or input / output terminals. Also,
Since the control during running is used without adding any special control for intermittently performing overexcitation, it can be performed with only a slight change in the conventional processing program. Further, since the engine 11 is started and the engine speed NE rises, the ON control is always started after waiting one second even if the engine speed exceeds 500 rpm. Therefore, as shown in FIG. Thus, the line pressure solenoid can be reliably turned on.

In the first embodiment, the engine speed N
When E exceeds 0, the control is switched from the always-on control to the normal control, and the control is returned from the normal control to the always-on control when one second elapses beyond 500 rpm. The control may be such that the hold excitation of the ON control is continued, and after one second, one or more overexcitations are performed to return to the hold excitation. In the first embodiment, the two transistors Q3 and Q4 and the drop resistor R1
Is used to set overexcitation and holding excitation of the line pressure solenoid SL. However, as shown in FIGS. 9 and 10, switching control of one transistor Q4 may be performed to realize overexcitation and holding excitation. As shown in FIG. 9, the CPU 16b provided in the automatic transmission control unit 10b turns on / off the transistor Q4 at a high speed via the transistor Q2 of the output circuit 17b, and the line pressure solenoid SL as shown in FIG. The voltage VSb is supplied. At this time, since the change in current is suppressed by the properties of the coil, a current ISb for realizing overexcitation and holding excitation similar to the current IS shown in FIG. 3 flows through the line pressure solenoid SL.

The control of the second embodiment will be described with reference to FIG. In the second embodiment, a sensor (switch) (not shown) for detecting whether or not the key is operated to the driving position of the starter motor is provided in addition to the key switch 22 in the first embodiment. The output of this sensor is input to the CPU 16 via the input circuit 15. Further, during the control shown in FIG. 5, the process of step 105 is performed by changing the flow shown in FIG.
1 is replaced by the flow shown in FIG. The description of the configuration and control common to the first embodiment will be omitted, and the processing shown in FIG. 11 will be described.

As shown in FIG. 11, in step 221, it is determined whether or not the throttle opening TVO exceeds 1/8. If it exceeds 1/8, go to step 225,
If it is 1/8 or less, the routine proceeds to step 222, where it is determined whether or not the engine speed NE is 0 rpm. If the engine speed NE exceeds 0 rpm, the process proceeds to step 226. If the engine speed NE is 0 rpm, the process proceeds to step 226.
Proceeding to 23, it is determined whether or not the vehicle speed VSP exceeds 5 km / h. If the vehicle speed VSP exceeds 5 km / h, the routine proceeds to step 227. When the accelerator pedal is not depressed (TVO is 1/8 or less), the engine is stopped (NE =
At 0), if the vehicle is in a stopped state (VSP is 5 km / h or less), the routine proceeds to step 224, where the flag F is set to 1.
That is, the always-on control is selected, and after the line pressure solenoid SL is over-excited once, the line pressure solenoid SL is maintained in the state of holding excitation.

At step 225, the throttle opening TV
It is determined whether O is greater than 1.5 / 8. 1.5 /
If it is less than 8, the routine proceeds to step 226, where it is determined whether or not the engine speed NE exceeds 1700 rpm.
If the engine speed NE is 1700 rpm or less, the routine proceeds to step 227, where it is determined whether or not the vehicle speed VSP exceeds 7 km / h. If the vehicle speed VSP is 7 km / h or less, the process proceeds to step 228. Any of the depressed state of the accelerator pedal (TVO exceeds 1.5 / 8), the start from the idle rotation state (NE exceeds 1700 rpm), and the substantial running state (vehicle speed VSP exceeds 7 km / h) If so, the routine proceeds to step 232, where the flag F is set to 0.
And That is, the normal control is selected, and the duty ratio of the line pressure solenoid SL is controlled as shown in FIG.

At step 228, it is determined whether or not the key switch 22 has been operated to the position for driving the starter motor. If it is the cell motor drive position, the routine proceeds to step 232, where the flag F is set to 0. If it is not the cell motor drive position, the flow is ended while the flag F is maintained as it is.
Steps 221 and 2 in the flowcharts of FIGS.
22, 223, 224, 106 and 107 correspond to the always-on control means of the present invention. Step 228 is the starter motor ON detecting means of the present invention, and steps 228, 232, 10
6, 109 correspond to the recovery means of the present invention.

According to the control of the second embodiment, the line pressure solenoid SL is always ON when the engine is stopped, so that noise of the line pressure solenoid SL unlike the normal control is not generated. Then, since the normal control is applied after the start of the starter motor, it is possible to avoid a situation in which the line pressure solenoid SL is kept in the OFF state by the holding excitation as in the case where the battery voltage VB is reduced by the always ON control. Is done.

The control of the third embodiment will be described with reference to FIGS. Here, during the control of the first embodiment shown in FIG. 5, the processing of steps 105, 106, 107 and 109 is replaced by the processing shown in FIG. The description of the configuration and control common to the first embodiment is omitted.

In the third embodiment, as shown in FIG. 12, when the key switch 22 is turned on at the time G, the line pressure solenoid SL repeats overexcitation of 3 ms and holding excitation of 17 ms for the line pressure solenoid SL. Is turned on. In this special ON state, the accelerator pedal is not depressed (T
VO is 1/8 or less), body is stopped (VSP is 5km)
/ H). And engine 1
Normal control is started at time H when 1 comes out of the idle rotation state and enters the start state (for example, when NE exceeds 1700 rpm). Since this special ON state does not include the OFF of the line pressure solenoid SL, the plunger does not vibrate as in the normal control, and the line pressure solenoid SL is
N is left. Even if the battery voltage VB decreases with the driving of the cell motor and the line pressure solenoid SL is unintentionally turned off, the line pressure solenoid SL is quickly restored to the on state by overexcitation.

As shown in FIG. 13, in step 321, it is determined whether or not the throttle opening TVO exceeds 1/8. If it exceeds 1/8, go to step 325,
If it is 1/8 or less, the routine proceeds to step 322, where it is determined whether or not the engine speed NE exceeds 1500 rpm. If the engine speed NE exceeds 1500 rpm, the process proceeds to step 326, but the engine speed NE becomes 15 rpm.
If it is less than 00 rpm, the routine proceeds to step 323, where the vehicle speed V
It is determined whether the SP exceeds 5 km / h. Vehicle speed V
If the SP exceeds 5 km / h, the flow proceeds to step 327. The throttle opening TVO is 1/8 or less, the engine speed NE is 1500 rpm or less, and the vehicle speed VSP is 5 km.
If it is equal to or less than / h, the process proceeds to step 324, where
And

In step 325, the throttle opening TV
It is determined whether O is greater than 1.5 / 8. 1.5 /
If it is less than 8, the routine proceeds to step 326, where it is determined whether the engine speed NE exceeds 1700 rpm.
If the engine speed NE is 1700 rpm or less, the routine proceeds to step 327, where it is determined whether or not the vehicle speed VSP exceeds 7 km / h. If the vehicle speed VSP is equal to or less than 7 km / h, the flow is terminated while the flag F is maintained as it is.
Throttle opening TVO exceeds 1.5 / 8, engine speed NE exceeds 1700 rpm, vehicle speed VSP is 7
km / h, step 3
The routine proceeds to 28, where the flag F is set to 0.

At step 329, whether the flag F is 1 or 0 is identified. If the flag F is 0, the routine proceeds to step 331, where the normal control is executed. In the normal control, the duty ratio of the line pressure solenoid SL is controlled as shown in FIG. On the other hand, if the flag F is 1, the routine proceeds to step 332, where the above-mentioned special ON state control is executed. The line pressure solenoid SL is driven at 50 Hz similarly to the normal control as shown in FIG. 12, but repeats overexcitation of 3 ms and holding excitation of 17 ms without interposing OFF.

According to the control of the third embodiment, after the key switch is turned on, the line pressure solenoid SL is kept in the ON state until the vehicle is started, so that noise of the line pressure solenoid SL unlike the normal control is not generated.

[0046]

According to the first or second aspect of the present invention, even if the battery voltage drops during driving of the cell motor and the line pressure solenoid is turned off unintentionally, overexcitation is performed after driving the cell motor. O for line pressure solenoid
The line pressure solenoid is turned off because it returns to the N state.
The situation of being left in a state is avoided. Further, since the timing at which the battery voltage drops is determined based on the engine speed, there is no need to provide a circuit for detecting the battery voltage, an input terminal, a program, and the like.

According to the third aspect of the present invention, the intermittent overexcitation is continued for a predetermined time even if the driving of the starter motor is not detected, so that the overexcitation by the battery voltage restored to the predetermined voltage level is achieved. ON of line pressure solenoid
The state is reliably recovered, and the ON state of the line pressure solenoid is reliably maintained by the holding excitation by the battery voltage recovered to the predetermined voltage level.

According to the fourth aspect of the present invention, since overexcitation and holding excitation are repeated throughout the engine stop state, even if the battery voltage drops when the cell motor is driven and the line pressure solenoid is turned off unintentionally, Then, the line pressure solenoid immediately returns to the ON state. Further, since the overexcitation and the holding excitation are repeated irrespective of the turning on of the starter motor, a means for detecting the battery voltage and a means for detecting the drive of the starter motor are unnecessary.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of the configuration and connection of an automatic transmission control unit.

FIG. 2 is an explanatory diagram of a configuration of an output circuit.

FIG. 3 is a time chart of control during running of a line pressure solenoid.

FIG. 4 is a time chart of a constant ON control of a line pressure solenoid.

FIG. 5 is a flowchart of control of the automatic transmission.

FIG. 6 is a flowchart of control according to the first embodiment.

FIG. 7 is a diagram showing a relationship between a throttle opening and a line pressure setting.

FIG. 8 is a diagram showing a relationship between a line pressure setting and a duty ratio.

FIG. 9 is an explanatory diagram of a configuration of another output circuit.

FIG. 10 is a time chart of another control during running of the line pressure solenoid.

FIG. 11 is a flowchart of control according to the second embodiment.

FIG. 12 is a time chart of control for holding a line pressure solenoid in an ON state.

FIG. 13 is a control flowchart of the third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Automatic transmission control unit 11 Engine 12 Automatic transmission 13 Output shaft 15 Input circuit 16 CPU 17 Output circuit 18 Memory 19 Power supply circuit 21 Battery 22 Key switch Q1, Q2, Q3, Q4 Transistor R1 Drop resistance SL Line pressure solenoid

Claims (4)

[Claims] In an automatic transmission control device that constantly keeps a line pressure solenoid of an automatic transmission in an ON state while an engine is stopped, when an engine stop state is detected, overexcitation is performed and then the line pressure solenoid is held and excited. A continuously ON control means for continuing the state, an engine speed detecting means for detecting that the engine speed is within a range corresponding to the driving of the starter motor, and an operation of the line pressure solenoid after the drive of the starter motor is detected. An automatic transmission control device, comprising: recovery means for performing overexcitation at least once. 2. An automatic transmission control device for continuously holding a line pressure solenoid of an automatic transmission in an on-state when an engine is stopped. When an engine stop state is detected, overexcitation is performed, and then the line pressure solenoid is held and excited. Constant ON control means for continuing the state, cell motor ON detection means for detecting that the key switch is at the cell motor driving position, and over-excitation of the line pressure solenoid is performed at least once after the driving of the cell motor is detected. An automatic transmission control device comprising a recovery unit. 3. The automatic transmission according to claim 1, wherein the recovery unit continues the intermittent overexcitation until a predetermined time elapses even if the driving of the starter motor is not detected. Control device. 4. An automatic transmission control device that constantly keeps a line pressure solenoid of an automatic transmission in an ON state when an engine is stopped, detects an engine stop state, and intermittently suppresses overexcitation until the vehicle reaches a start state. An automatic transmission control device, characterized in that the line pressure solenoid keeps maintaining the excited state.